rtc_base/experiments/field_trial_parser_unittest.cc

/*
 *  Copyright 2018 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */
#include "rtc_base/experiments/field_trial_parser.h"
#include "rtc_base/gunit.h"
#include "system_wrappers/include/field_trial.h"
#include "test/field_trial.h"

namespace webrtc {
namespace {
const char kDummyExperiment[] = "WebRTC-DummyExperiment";

struct DummyExperiment {
  FieldTrialFlag enabled = FieldTrialFlag("Enabled");
  FieldTrialParameter<double> factor = FieldTrialParameter<double>("f", 0.5);
  FieldTrialParameter<int> retries = FieldTrialParameter<int>("r", 5);
  FieldTrialParameter<bool> ping = FieldTrialParameter<bool>("p", 0);
  FieldTrialParameter<std::string> hash =
      FieldTrialParameter<std::string>("h", "a80");

  explicit DummyExperiment(std::string field_trial) {
    ParseFieldTrial({&enabled, &factor, &retries, &ping, &hash}, field_trial);
  }
  DummyExperiment() {
    std::string trial_string = field_trial::FindFullName(kDummyExperiment);
    ParseFieldTrial({&enabled, &factor, &retries, &ping, &hash}, trial_string);
  }
};

enum class CustomEnum {
  kDefault,
  kRed,
  kBlue,
};
}  // namespace

// Providing a custom parser for an enum can make the trial string easier to
// read, but also adds more code and makes the string more verbose.
template <>
absl::optional<CustomEnum> ParseTypedParameter<CustomEnum>(std::string str) {
  if (str == "default")
    return CustomEnum::kDefault;
  else if (str == "red")
    return CustomEnum::kRed;
  else if (str == "blue")
    return CustomEnum::kBlue;
  return absl::nullopt;
}

TEST(FieldTrialParserTest, ParsesValidParameters) {
  DummyExperiment exp("Enabled,f:-1.7,r:2,p:1,h:x7c");
  EXPECT_TRUE(exp.enabled.Get());
  EXPECT_EQ(exp.factor.Get(), -1.7);
  EXPECT_EQ(exp.retries.Get(), 2);
  EXPECT_EQ(exp.ping.Get(), true);
  EXPECT_EQ(exp.hash.Get(), "x7c");
}
TEST(FieldTrialParserTest, InitializesFromFieldTrial) {
  test::ScopedFieldTrials field_trials(
      "WebRTC-OtherExperiment/Disabled/"
      "WebRTC-DummyExperiment/Enabled,f:-1.7,r:2,p:1,h:x7c/"
      "WebRTC-AnotherExperiment/Enabled,f:-3.1,otherstuff:beef/");
  DummyExperiment exp;
  EXPECT_TRUE(exp.enabled.Get());
  EXPECT_EQ(exp.factor.Get(), -1.7);
  EXPECT_EQ(exp.retries.Get(), 2);
  EXPECT_EQ(exp.ping.Get(), true);
  EXPECT_EQ(exp.hash.Get(), "x7c");
}
TEST(FieldTrialParserTest, UsesDefaults) {
  DummyExperiment exp("");
  EXPECT_FALSE(exp.enabled.Get());
  EXPECT_EQ(exp.factor.Get(), 0.5);
  EXPECT_EQ(exp.retries.Get(), 5);
  EXPECT_EQ(exp.ping.Get(), false);
  EXPECT_EQ(exp.hash.Get(), "a80");
}
TEST(FieldTrialParserTest, CanHandleMixedInput) {
  DummyExperiment exp("p:true,h:,Enabled");
  EXPECT_TRUE(exp.enabled.Get());
  EXPECT_EQ(exp.factor.Get(), 0.5);
  EXPECT_EQ(exp.retries.Get(), 5);
  EXPECT_EQ(exp.ping.Get(), true);
  EXPECT_EQ(exp.hash.Get(), "");
}
TEST(FieldTrialParserTest, IgnoresNewKey) {
  DummyExperiment exp("Disabled,r:-11,foo");
  EXPECT_FALSE(exp.enabled.Get());
  EXPECT_EQ(exp.factor.Get(), 0.5);
  EXPECT_EQ(exp.retries.Get(), -11);
}
TEST(FieldTrialParserTest, IgnoresInvalid) {
  DummyExperiment exp("Enabled,f,p:,r:%,,:foo,h");
  EXPECT_TRUE(exp.enabled.Get());
  EXPECT_EQ(exp.factor.Get(), 0.5);
  EXPECT_EQ(exp.retries.Get(), 5);
  EXPECT_EQ(exp.ping.Get(), false);
  EXPECT_EQ(exp.hash.Get(), "a80");
}
TEST(FieldTrialParserTest, ParsesOptionalParameters) {
  FieldTrialOptional<int> max_count("c", absl::nullopt);
  ParseFieldTrial({&max_count}, "");
  EXPECT_FALSE(max_count.Get().has_value());
  ParseFieldTrial({&max_count}, "c:10");
  EXPECT_EQ(max_count.Get().value(), 10);
  ParseFieldTrial({&max_count}, "c");
  EXPECT_FALSE(max_count.Get().has_value());
  ParseFieldTrial({&max_count}, "c:20");
  EXPECT_EQ(max_count.Get().value(), 20);
  ParseFieldTrial({&max_count}, "c:");
  EXPECT_EQ(max_count.Get().value(), 20);
  FieldTrialOptional<std::string> optional_string("s", std::string("ab"));
  ParseFieldTrial({&optional_string}, "s:");
  EXPECT_EQ(optional_string.Get().value(), "");
  ParseFieldTrial({&optional_string}, "s");
  EXPECT_FALSE(optional_string.Get().has_value());
}
TEST(FieldTrialParserTest, ParsesCustomEnumParameter) {
  FieldTrialParameter<CustomEnum> my_enum("e", CustomEnum::kDefault);
  ParseFieldTrial({&my_enum}, "");
  EXPECT_EQ(my_enum.Get(), CustomEnum::kDefault);
  ParseFieldTrial({&my_enum}, "e:red");
  EXPECT_EQ(my_enum.Get(), CustomEnum::kRed);
}
}  // namespace webrtc